From the author of

From the author of

Introduction

TSQLDataset is the unidirectional dataset used for retrieving data
from a dbExpress-supported server. This dataset can be used to represent data in
a database table, a selection query, or the results of a stored procedure. It
can also execute a stored procedure.

TSQLDataset's key properties are CommandType and
CommandText. The value selected for CommandType determines how
the content of CommandText will be used. Possible values for
CommandType are listed in Table 1 and in the Delphi help file.

Table 1 CommandType Values (from Delphi Online Help)

CommandType

Corresponding CommandText

ctQuery

An SQL statement that the dataset executes.

ctStoredProc

The name of a stored procedure.

ctTable

The name of a table on the database server. The SQL dataset automatically
generates a SELECT statement to fetch all the records of all the fields
in the specified table.

When the CommandType property contains the
ctQuery value, CommandText is an SQL statement. This statement
might be a SELECT statement that returns a result set such as the
following SQL statement: SELECT * FROM CUSTOMER.

If CommandType is ctTable, CommandText refers to a
table name on the database server. The CommandText property will change
to a drop-down list. If this is an SQL database, any SQL statements needed to
retrieve data are automatically generated.

If CommandType has the value ctStoredProc,
CommentText will then contain the name of a stored procedure to
execute. This would be executed by calling the TSQLDataSet.ExecSQL()
method rather than by setting the Active property to True.
Note that ExecSQL() should be used if CommandType is
ctQuery and the SQL statement doesn't result in a result set.

Retrieving Table Data

To extract table data using the TSQLDataset, you simply set the
TSQLDataSet.CommandType property to ctTable. The
CommandText property will change to a drop-down list from which you can
select the table name.

Displaying Query Results

To extract data from a query select statement, simply set the
TSQLDataSet.CommandType property to ctQuery. In the
CommandText property, you can enter a query select statement such as
Select * from Country. This is demonstrated in the example on the CD
under the QueryData directory.

Displaying Stored Procedure Results

Given a stored procedure that returns a result set such as the InterBase
procedure that follows, you can extract the result set using a
TSQLDataset component: